66438945 has 48 divisors (see below), whose sum is σ = 119031120. Its totient is φ = 34265088.

The previous prime is 66438937. The next prime is 66438949. The reversal of 66438945 is 54983466.

It can be written as a sum of positive squares in 8 ways, for example, as 13905441 + 52533504 = 3729^2 + 7248^2 .

It is not a de Polignac number, because 66438945 - 2³ = 66438937 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a zygodrome in base 3.

It is a self number, because there is not a number n which added to its sum of digits gives 66438945.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66438949) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 212109 + ... + 212421.

It is an arithmetic number, because the mean of its divisors is an integer number (2479815).

Almost surely, 2^66438945 is an apocalyptic number.

It is an amenable number.

66438945 is a deficient number, since it is larger than the sum of its proper divisors (52592175).

66438945 is a wasteful number, since it uses less digits than its factorization.

66438945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 466 (or 463 counting only the distinct ones).

The product of its digits is 622080, while the sum is 45.

The square root of 66438945 is about 8151.0088332672. The cubic root of 66438945 is about 405.0179233037.

The spelling of 66438945 in words is "sixty-six million, four hundred thirty-eight thousand, nine hundred forty-five".